This invention relates to a vertically oriented centrifugal pump, and more specifically, although not exclusively, to a vertically oriented pitot pump. This invention also relates to a method for accessing such a vertical pump, for example, for repair or maintenance operations.
Pitot pumps are centrifugal pumps which have an impeller or rotor rotatably driven inside a housing. A pitot tube is disposed inside the impeller for capturing and redirecting rotating fluid from the impeller to an outlet. To that end, the pitot tube has a circumferential input stub located near the periphery of the impeller cavity, a radially extending central portion and an axially extending output stub connected to the pump outlet.
Pitot pumps are known, for example, from U.S. Pat. Nos. 3,384,024 to King and 3,999,881 to Crichlow.
Pitot pumps are generally used in a horizontal orientation in commercial applications. The pump impeller rotates about a horizontal axis. Such pitot pumps are advantageous in that pump maintenance, such as the replacement of seals, can be performed expeditiously particularly in comparison to other types of pumps. Maintenance can be undertaken without removing the impeller and without disconnecting the bearings.
Many non-pitot type pumps are disposed in a vertical orientation to preserve floor or ground space, which is at a premium. In a vertical pump configuration, the drive motor is located in vertical alignment with the rotor.
The disposition of a pitot type pump in a vertical orientation is not generally feasible owing to a substantial increase in the difficulty of changing the seals. The problem arises, therefore, to enable or facilitate pump maintenance where a pitot pump is placed in a vertical configuration.